1. Field of the Invention
The present invention relates to methods and devices used to repair damaged pipelines, walls of physical structures and holding tanks. More particularly, the present invention relates to the field repair and patching of undesirable ruptures, holes or punctures in a previously constructed and/or installed wall of a pipeline, tank or other physical structure.
2. Description of Related Art
The repair, and especially the field repair, of punctures in pipelines, storage or chemical processing tanks, and other physical structures is a matter of considerable import in numerous industrial and domestic settings, e.g. septic tanks and petroleum pipelines. The approach by a repair technician to the puncture is often limited to an interior side of the puncture, and a timely repair is best executed from an exterior side only. Welding tools and techniques are sometimes effective, but only where the pipeline, structure or tank is made of a relatively few appropriate materials, e.g. steel or aluminum. Welding can be dangerous to apply, requires rigorous technical training and expensive tooling, can cause obvious and non-obvious structural damage to the pipeline, structure or tank, is difficult to monitor for quality and may be difficult to perform in remote areas away from required facilities.
A variety of expanding element assemblies, generally referred to as molly bolts, are used to establish an opposing surface against an interior side of a wall. The molly bolt includes an expanding element and a threaded bolt, where the expanding element is initially passed through a puncture and the threaded bolt is then rotatably driven into the expanding element. It is intended by the design of the molly bolt that the shape of the expanding element changes to form a surface as the threaded bolt is advanced into the expanding element and through the puncture, and where a perimeter of the formed surface grows larger than the puncture. The perimeter of the formed surface is then forced against the interior side of the pipeline or wall as a result of the advance of the bolt into the expanding element. Molly bolts are often used to establish load bearing anchor points in drywall and other materials.
Molly bolts do not establish sealing surfaces of continuous perimeter around a puncture, hole or rupture. Molly bolts are, therefore, not useful as hole plugs to repair and seal holes in physical structures, such as tanks and pipelines, that process, contain or store chemicals or materials, to include vapors or liquids.
There is, therefore, a long felt need in various domestic and industrial arts to provide a widely applicable and easily attached hole plug of simple and inexpensive construction and that requires access to only one side of the hole for installation.
It is therefore an object of the present invention to provide an apparatus to repair a rupture, hole or puncture in a wall of a pipeline, a tank or other physical structure, optimally in a permanent and leak-proof manner;
It is another object of the present invention to provide an apparatus constructed with simple and inexpensive materials to repair a rupture, hole or puncture of a wall of a pipeline, a tank or other physical structure;
It is an additional object of the present invention to provide an apparatus to repair ruptures, holes and punctures in a wall of a pipeline, tank or other physical structure, where the apparatus is usable with a wide variety of pipeline, tank and structural materials;
It is a further object of the present invention to provide an apparatus and method of installation of the apparatus that enables the repair of a rupture, hole or puncture of a wall of a pipeline, tank or other physical structure where access by a repair technician to only one side, or an exterior side, of the wall is desirable, possible or required;
It is still another object of the present invention to provide an apparatus and a method to effectively repair a rupture, hole or puncture in a wall of a pipeline, tank or other physical structure without the use of high temperature tools, such as welding equipment, and whereby the repair is executed at an ambient temperature, thereby reducing a risk of uncontrolled fire and/or of heat induced structural damage of the wall;
It is yet a further object of the present invention to provide an apparatus that is manufacturable in a variety of sizes, whereby an appropriately sized embodiment is selected and used in view of the magnitude of the specific rupture, hole or puncture under repair; and
It is still another object of the present invention to provide an apparatus that is quickly executable in a field environment and enables a rapid repair of ruptures, holes or punctures in a wall of a pipeline, tank or other physical structure.
These and other objects and advantages of the present invention are achieved by providing an apparatus and method to repair ruptures, holes and punctures through a wall of a pipeline, tank or other physical structure. Generally speaking, the present invention provides a set of apertured washers secured about a threaded shank of a bolt and captured between a head of the bolt and a threaded nut. The set of washers includes at least two notched washers, a sealing washer and an exterior washer. The aperture of each washer is dimensioned to allow passage of the threaded shank through each washer. In operation, all of the washers are located about the threaded shank of the bolt. The set of washers is positioned along the threaded shank, in order from the head of the bolt to the nut as follows: a first notched washer, a second notched washer followed by any additional washers, one or two sealing washers and the exterior washer.
The method of the present invention includes the steps of identifying a hole for repair and optionally preparing the hole, by cleaning and filing for example, to create a prepared hole having a solid edge with a substantially flat interior side and a substantially flat exterior side to which the present invention may be secured. The size and shape of the hole may be increased to form a prepared hole in order to allow a passage through the wall of the head of the bolt, notched washers and optionally an internal sealing washer. The method of the present invention allows for the preparation and/or selection of varying sizes of the elements of certain alternate preferred embodiments, where a best fit preferred embodiment may be especially dimensioned and prepared, or selected from an inventory of preferred embodiments to most closely match the size and shape of the prepared hole.
The size of the prepared hole allows passage of the bolt head, the washers and the optional internal sealing washer. The prepared hole can be oval in shape with a minimum first axial dimension that allows passage of the bolt head and a minimum second axial dimension that allows passage of the washers. Although the optional internal sealing washer, and/or an optional external sealing washer, present a sealing surface area that is larger than the prepared hole, the internal sealing washer is elasticity deformable to allow bending and compressing of the internal sealing washer during insertion through the hole.
The preferred embodiment of the notched washers is shaped as a flattened sheet with a circular internal aperture and an essentially circular periphery. The periphery of the preferred embodiments is formed as a circle cut along a chord and with the chordal segment removed. The resultant periphery therefore present a major axis and a minor axis, where the major axis is longer than the minor axis. In certain preferred embodiments, the chordal cut passes through the internal aperture and creates an open gap of the internal aperture. This gap is smaller in length than the diameter of the bolt shank in order maintain the captivation of the notched washer by the bolt shank. The notched washers may be identical within a particular embodiment in order to reduce manufacturing costs.
In some embodiments, the face of the washers may have other contours to properly fit the surface of the tank. For example, if the curved wall of a cylindrical tank were being patched, the face of the washers may be curved so that, when in place, the curved face washers will press evenly against the wall of the tank. Other shapes, such as compound curves, angles, bends, or any other practical or desirable shape, are also envisioned.
The peripheries of the notched washers of various alternate embodiments are shaped in other forms than circular and that present a major axis and a minor axis, e.g. rectangular, oval and oblong shapes. The minor axis allows the notched washer to be inserted through a hole where the hole has a smaller diameter than the length of the major axis. After insertion, the preferred embodiment provides two or more notched washers that are then fanned out to create a circular combined periphery with a diameter equal to the length of the major axis. Alternate notched washer shapes and designs will create differently shaped combined peripheries.
The present invention may also be used to secure large openings by using a plurality of sets of: washers, sealing washer(s), nut, and bolt. In this case, a plate or other larger object may be placed covering the hole, the plate would then be secured around the opening using as many of the hole plugs of the present invention as is necessary or desired to successfully secure the plate. To ensure proper sealing, a resilient member may be added between the plate and the wall around the hole.
The head of the bolt and the notched washers are first inserted through the prepared hole from an exterior side and beyond an interior side of the wall. The method of the present invention includes an insertion of each notched washer through the prepared hole, where the size and shape of the prepared hole allow this insertion, and where the size and shape of the prepared hole obstruct a passage of the notched washers through the prepared hole when the notched washers have been inserted as described and are fanned out to form a pressure surface. Each notched washers is notched prior to installation in order to reduce their individual maximum surface areas and thereby ease passage of each notched washer through the prepared hole. In addition, the optional internal sealing washer may be passed through the hole and beyond the interior side of the wall. The optional internal sealing washer is constructed of material and formed by design to flexibly and elastically deform during transit through the prepared hole. Before or after insertion of the internal sealing washer, the notched washers are fanned out to form an internal pressure surface for pressing either directly against the interior side of the wall or optionally for pressing the internal sealing washer against the interior side of the wall. The threaded nut, remaining located exterior to the hole, is next advanced along the threaded shank of the bolt and towards the bolt head. This advancement of the threaded nut drives the exterior washers, if used, towards the exterior side of the wall whereby the optional external sealing washer is pressed against the exterior side of the wall.
When fully installed, those preferred embodiments which include the insertion of the optional internal sealing washer through the hole, press the head of the bolt against the fanned out notched washers, whereby the pressure surface of the notched washers is forced against the internal sealing washer and the internal sealing washer is thereby pressed against the interior side of the wall. In those preferred embodiments of the present invention which do not include the placement of the optional internal sealing washer against the interior of the wall, the pressure surface formed by the fanned out notched washers is pressed directly against the interior of the wall by the bolt head during and after installation, and the threaded nut threadably engages the threaded shank of the bolt and drives the exterior washers towards the exterior side of the wall. The exterior washers thereby presses the external washer against the exterior side of the wall. The pressure of the threaded nut against the exterior washer and the pressure of the bolt head against the fanned out notched washers insure that the external sealing washer and/or the internal sealing washer are sufficiently forced against the exterior side and/or the interior side of the wall to effectively seal the hole.
Certain alternate preferred embodiments of the present invention are configured with an alignment tooth or teeth on the bolt head and matching alignment receivers on the notched washers whereby the pressure surface area formed thereof is repeatably and reliably formed by the fanned out washers.
Certain preferred embodiments of the present invention further comprise one or more multi-plane washers, where each multi-plane washers includes a flat intermediate surface and a flat raised surface. The raised surface aligns with one or more notched washers and/or one or more additional multi-plane washers to create a uniform pressure surface plane for pressing against either the internal sealing washer or the interior side of the wall. When the multi-plane washer is pressed along the axis of the threaded shank and towards the interior side of the wall, the intermediate surface plane consequently presses one or more notched washers and/or additional multi-plane washers from behind the uniform pressure surface. The multi-plane washer thereby combines with and stabilizes a fanned out formation of one or more notched washers and/or one or more multi-plane washers into the uniform pressure surface plane and thus supports the sealing of the hole. This style of washer may or may not include alignment holes.
Any excess length of the threaded shank protruding outwards from the threaded nut after installation of the present invention may be cut off or removed. The removal of some or all excess length may be desired for safety reasons and to eliminate an obstruction point on the exterior of the wall. In certain applications where tampering or unauthorized disassembly of the installed hole plug is to be discouraged, specialized locking or securing nuts, or nuts with locking elements, may be used to hamper or prevent improper removal of the hole plug. Locking elements such as teflon bands and/or engaging flanges that bite into the wall are included in the design of locking or securing nuts as locking elements in various preferred embodiments of the present invention. Certain alternate preferred embodiments of the present invention employ separate locking washers as locking elements. Glues or adhesive substances such as lock-tite may also be employed to more strongly seal the hole plug in place and impede removal.
The present invention thus provides a widely applicable, low-cost, rapidly employed and easy to install hole plug of varying model sizes that requires access by the installation technician to only one side, i.e. the exterior side, of a wall of a pipeline, tank or other physical structure.